Keep up the good work, Gareth! I'm still on page 31, but taking them round the cycle from memory.
My brain trips up sometimes, getting confused between tonal harmony and alternating I-V harmony. In for example the key of C, tonal harmony has the G7 on the V chord - no surprise there! So I find myself scratching my head sometimes when the G bass is instead a I chord, and the 4th and 6th notes of the key are both a V7 chord. LOL. I keep forgetting, of course, that these shapes are for over a static chord, and therefore the Tonal rules do not apply. Looking ahead, I see Chapter 2 might shed some light on all of this, but I'll wait until I'm comfortable with the various shapes over a static chord before launching into it.